Noun
the size of a book whose pages are made by folding a sheet of paper twice to form four leaves
Source: WordNetDescription: Paperback, 4to, 1190 pp. with index. Source: Internet
Hardcover, 4to, 125 pp. with many b/w illustrations and maps. Source: Internet
Description: Hardcover, 4to, 256 pp with index. Source: Internet
Hardcover, large 4to, dj with glassine outer-wrap, text in French, 102 pp, copiously illustrated in color and b/w. Source: Internet
Hardcover, 4to, 500pp. with index. Source: Internet
Original illustrated paper covers, 4to, 48 pages. Source: Internet